The present invention relates to a guide for controlling the transfer of articles between oppositely running conveyors.
There are many arrangements wherein oppositely running conveyors disposed side by side and generally parallel are used for transporting articles. A common such use is in conveying accumulator systems utilized between an upstream delivery station and a downstream receiving station to accumulate or store articles when the capacity of the downstream receiving station is either shut down or run at a speed wherein it cannot handle the number of articles being fed by the upstream delivery station. Such accumulator systems are well known to those skilled in the art. One particular accumulator is disclosed in U.S. Pat. No. 4,018,325. An additional prior art accumulator system is disclosed in U.S. Pat. No. 4,513,858. With such accumulator systems, and in any other system wherein articles are transferred from one conveyor running in one direction onto another conveyor running in an opposite direction, a device must be provided for controlling the transfer of the articles from one conveyor onto the other.
The present invention relates particularly to an article guide for a transport member or device utilized for controlling the transfer of articles from a first conveyor running in a first direction onto a second conveyor running in a second opposite direction.
Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present invention has particular application in conveyor accumulator systems wherein oppositely running and parallel conveyors are used to accumulate and store articles between an upstream receiving station and a downstream delivery station. One such accumulator system is disclosed and described in U.S. Pat. No. 6,260,688 (co-pending U.S. patent application Ser. No. 09/235,888) entitled xe2x80x9cApparatus for Controlling the Flow of Articles.xe2x80x9d In particular, the present invention relates to an improvement to the apparatus described in U.S. Pat. No. 6,230,874 B1 entitled xe2x80x9cApparatus for Controlling the Flow of Articlesxe2x80x9d.
Although conveyors are a feature of the present invention, conventional conveyors are well known to those skilled in the art and need not be described herein in great detail. The features of the conveyors necessary for an understanding of the invention will be sufficiently described.
In accordance with the objects and purposes of the invention, an apparatus is provided for controlling the flow of articles. This apparatus includes a first conveyor driven in a first direction to convey articles thereon in the first direction. A second conveyor is driven in a second opposite direction to convey articles thereon in the opposite direction. As mentioned above, the first and second conveyors may be used in a conventional accumulator system. The conveyors extend generally side by side and parallel with a constant space defined between the inside edges thereof.
A movable transport member is disposed generally across and movable along the space defined between the conveyors. The transport member has a drive member that may be drivingly engaged simultaneously by the first and second conveyors so that the drive member continuously rotates as either of the first or second conveyors moves. The transport member will move linearly between the conveyors so long as a speed differential exists between the conveyors. In other words, if both conveyors are moving linearly in opposite directions but at the same speed, the transport member remains stationary relative to the conveyors but will rotate. If the conveyors are moving in opposite directions but at different speeds, the transfer member will rotate and also move linearly in the direction of the faster conveyor.
In a preferred embodiment, the drive member comprises a toothed wheel that is simultaneously engaged by drive lugs on each of the conveyors.
The transport member also includes an article transfer member. This article transfer member is operably disposed transversely relative to the conveyors to contact and transfer articles from the first conveyor to the second conveyor along a transfer path.
In one preferred embodiment of the invention, the article transfer member further includes an endless drive belt that is disposed along the transfer path so as to contact and move articles therealong. This drive belt may run in an endless path between the drive member and article transfer member. The drive belt is drivingly engaged by the drive member, for example by a belt drive wheel that is operably connected to or driven by the drive member.
In a preferred embodiment, the major components of the movable transport member are mounted or carried on pivotally mounted support members or plates. For example, the article transfer member is preferably mounted on a rear support plate and the drive member is mounted on a front support plate. These front and rear support plates are pivotal relative to each other at a common pivot point. The article transfer member may further include a dead plate that is disposed so as to extend between the conveyors along the transfer path. The articles moved between the conveyors are moved over this dead plate. The dead plate is carried by a support that is also pivotally mounted at the common pivot point but at a different height or level.
The supports or plates for the drive member, article transfer member, and dead plate are pivotally mounted relative to each other to provide for relative movement between the components as the transport member moves through curves defined by the conveyors. It is preferred to precisely control the relative movement between the components so that the flow of articles between the conveyors is not interrupted and is maintained at a relatively constant rate through the conveyor curves. In this manner, in a preferred embodiment, the front and rear support plates and dead plate support are engaged or connected by a gear mechanism so that pivotal movement of either of the front or rear support plates is transferred to the other of the respective front and rear support plates and to the dead plate support as the transport member moves along the conveyor curves. This gear mechanism preferably has a different gear ratio between the front and rear support plates as compared to the dead plate support. The gear ratio for the horseshoe guide support is selected to ensure that the horseshoe guide remains substantially perpendicular to the conveyors as the transport member moves along the conveyor curves.
It should be appreciated that any manner of gear mechanism may be utilized to properly gear the support plates together. In one preferred embodiment, the gear mechanism is mounted to the front support plate and comprises a first gear engaged with the rear support plate and a second gear engaged with the dead plate support. The different gears define the different gear ratios.
In one embodiment of the invention, the article transfer member includes an idler wheel. The transfer path for the articles is defined between the drive belt and a circumferential portion of the idler wheel. The articles may move along the idler wheel as they are transferred between the conveyors. The idle wheel may thus be formed of a relatively low friction producing material so as not to impede the operation of the drive belt that engages and moves the articles.
The article transfer member may also include a rigid guide member. This guide member generally defines the transfer path between the conveyors. The drive belt may be supported by and movable along this guide member. The guide member is carried by a support member that is engaged by at least one of the front, rear, and dead plate supports. The guide member support also includes oppositely extending guide arms that are movable in guide ways defined in the first and second conveyors. Thus, it should be understood that the guide member support will also pivot as the transport member moves through the conveyor curves.
In one preferred embodiment of the invention, a belt tensioning device is carried by the drive member. This belt tensioning device may have various configurations and, in one embodiment, includes belt guides around which the drive belt runs. These belt guides are pivotally mounted relative to each other and interconnected by a tension device, such as a spring or similar device. The belt tension is adjusted by adjusting the position of the spring relative to the belt guide. The belt tensioning device moves with the guide member so that belt tension is relatively constant at all times.
It is further preferred to include a rigid linkage member interconnected between at least one of the belt guides and the rigid guide member carried by the article transfer member. This rigid linkage member ensures that pivotal movement of the guide member is imparted to the belt guide as the transport member moves through the conveyor curves so that the pivotal movement of the guide member will cause the belt guides to change position accordingly to compensate for the change in position between the guide member and drive member. The guide member prevents advancing or retarding of the belt when entering or exiting curves. This causes the belt to move at a constant speed relative to the conveyor movement, which is necessary to maintain constant spacing of the packages being accumulated on the conveyor. In this manner, a relatively constant article conveying speed for the drive belt is maintained through the conveyor curve.
The present invention may also include a resilient article guide for maintaining articles of different dimensions in alignment as they are transferred between the oppositely running conveyors. Sometimes the dimensions of the articles vary due to damaged packaging, etc. even when only a single desired dimension article is being transported from one conveyor to another by the article transport member. In order to maintain these articles, such as juice boxes, in alignment as they are moved from the transport member onto the adjacent conveyor, a resiliently biased article guide is used with the transport member. It includes an arcuate plate that can be moved out readily from the transport member by enlarged packages without causing binding of the packages as they exit the transport member.
In still a further embodiment of the invention, the article transfer member comprises a driven rotatable member having an article contacting surface, the transfer path being defined between the drive belt and a circumferential portion of the driven rotatable member such that articles are contacted and compelled along the transfer path by the drive belt and the driven rotatable member. In one particular embodiment, the idler wheel described in the previous embodiment is drivingly coupled to the drive member and defines the driven rotatable member.
In a particular embodiment, a drive mechanism is provided between the drive member and the rotatable member to transfer a driving force from the drive member to the rotatable member. The drive mechanism may be any manner of conventional transmitting device, for example, a gear drive, linkage, transmission, etc. In a desirable embodiment, the drive mechanism is a belt drive and may include, for example, a belt disposed around a drive pulley assembly configured on and driven by the drive member and a pulley assembly rotationally coupled with the driven rotatable member.
The drive mechanism may be disposed above the conveyors such that articles are compelled along the transfer path below the drive mechanism.
In the embodiment wherein the drive member is carried by a front support and the article transfer member is carried by a rear support that is pivotally mounted relative to the front support, the drive mechanism should accommodate for relative pivotal movement between the supports. A flexible drive element, such as the belt drive mentioned above, suffices in this regard.
The invention will be described below in greater detail by reference to embodiments disclosed in the attached figures.